Seal assemblies are used between rotational components in various applications. Seal assemblies may be used to provide an air and/or liquid seal between a stator and a rotor in a rotational system. Examples of rotational systems include gearboxes, engines, pumps, transmissions, compressors, transfer cases, differentials, and roller mills. Rotating components in the rotational system generally require lubrication during operation and a seal assembly may be used to prevent lubricant leaks out of the rotational system. In a typical rotor and stator configuration, the rotor and stator are prevented from contacting one another. The rotor rotates at high speeds such that if a surface of the rotor contacts a surface of the stator, frictional heat develops that wears the parts and decreases efficiency of the rotational system. Thus, a non-contacting or labyrinth type seal is used to prevent lubricant leaks in the system.
The use of a non-contacting seal or labyrinth seal, however, has drawbacks. One drawback is that the lubrication eventually may leak out of the gap required to prevent contact of the rotor and stator. Another drawback is that the seal may be unable to prevent external environmental contaminants from entering the shaft seal assembly when exposed to extreme environmental conditions. Lastly, labyrinth seals may be inefficient in sealing across high pressure differentials.